C. James Frush, the attorney representing store owner Brian Borgelt, said he will appeal the revocation in federal court. He said Wednesday his client will sell the store to a friend, Chris Kindschuh, if the ATF grants Kindschuh a license.

Borgelt, 38, a former Army Ranger and military sniper instructor, did not immediately return calls for comment Wednesday.

A .223-caliber Bushmaster AR-15 carbine, found with sniper defendants Lee Boyd Malvo and John Allen Muhammad when they were arrested in October, was traced to the store and linked to the Washington, D.C.-area killings.

It was one of dozens of weapons that went missing from Bull's Eye, Kelvin Crenshaw, agent in charge of the ATF office in Seattle, told the Seattle Post-Intelligencer.

"We feel what we've done is reasonable and within the bounds of the law to protect the public," Crenshaw said Tuesday.

Malvo and Muhammad have been linked to 20 shootings, including 13 deaths in Virginia, Maryland, Georgia, Alabama, Louisiana and Washington, D.C.

The $1,600 weapon, a civilian version of the M-16 military assault rifle, was on prominent display before it vanished from the store in July, investigators determined. The Seattle Times reported in April that Malvo told authorities he stole it.

Even if the store had immediately notified the ATF when the gun disappeared, Frush said, "It would have had no impact at all on the tragedy back East."

Besides revoking the license, the ATF reportedly has referred its findings to the U.S. attorney's office for a decision on charges against Borgelt. He and the store are being sued by relatives of nine sniper victims.

Frush said federal record-keeping regulations were violated at the store, but license revocation is unjustified because the violations were not willful.

He said about 50 firearms were missing from an inventory of 25,000, a rate he maintained falls within industry standards. Other reports have put the total missing at more than 200 weapons, but no figures have been confirmed.